In many activities, such as, but not limited to sports, a plurality of events, such as balls, runs, downs, goals, and the like, occur. In general, these events are tracked, and indicia related to the events are displayed to participants and spectators. For example, in basketball, it is important to keep track of and display the number of fouls of each player. In baseball, it is important to keep track of and display the balls, strikes and outs as well as the runs of the game. In each of these sports, the indicia (e.g., numbers) are typically displayed on an electronic scoreboard that is visible to everyone, including spectators and participants.
Football presents a similar yet distinct problem. In football, an important event that must consistently be visible to players, officials, and spectators is what down it is. Although the current down is often kept on an electronic scoreboard, it is also necessary for the down to be maintained on the field along the sidelines at a location visible to the players and officials. Not only must the players and officials be able to quickly see what down it is by referring to the down marker on the field, in many situations, especially high school and junior football, the down marker on the field may be the only indicator of the downs for the spectator.
One type of numerical down marker that is used in football consists of a flip card device mounted on a stake. This flip card device normally has a set of four cards. Each card has a single number painted thereon (either 1, 2, 3 and 4), and the cards are joined together by two rings so that the cards can be flipped forward or backward to display the proper down. One of the problems with this type of down marker is that it is hazardous to the players in the game. The individual cards have sharp edges and are in no way provided with any protective padding. Since the down marker must be kept on the sidelines of the playing field at the line of scrimmage, a player will often run into, or be tackled into, the down marker. This can cause serious injuries to the players and to others in the immediate vicinity. An increasing number of players are injured in football, and any form of safety or protection to the player is desirous and needed for the game.
Another problem with the flip card device is that the rings on which the numbers are mounted are easily broken. When a ring breaks or when a number breaks off of the ring, the number becomes crooked and difficult for the players, officials and spectators to see. The flip card device is also bulky and slow to operate.
It is also possible to display numbers, such as prices in the retail situation or downs in the game of football, by means of an electronic number indicator. However, an electronic device to display numbers is often too expensive to be practical in many applications. The cost of continuously running an electric price board in a retail store would be prohibitive in most cases. In many sports, and especially in football, it is impractical to use an electronic number device as a sideline down marker, particularly in high school and junior league football. Providing an AC operated device would be impractical if not impossible, and it would also be costly and impractical to employ a battery operated device.
Other mechanical types of devices have been developed for the purpose of keeping track of downs. As noted above, the players sometimes run into the devices during the playing of games, oftentimes with substantial force. The prior art devices of this type have an internal structure that floats within an external frame and, because it is subject to significant forces when struck by one or more player, is often shook violently. Further, the prior art used a significant number of interior parts, especially sliding elements, so that the prior art was significantly subject to damage and failure.